The Senate leader has to keep his members in line, satisfy an angry base, protect the Democrats in the coming midterms, and oh yeah, deal with Trump.

For over a year, Senate Minority Leader Chuck Schumer has kept his caucus in line, holding Democrats in lock step on the most high-profile votes of 2017. This has been vital to Democratic opposition to the Trump administration’s most extreme policies. If even one Senate Democrat had broken rank on the healthcare vote, the Affordable Care Act would have been repealed; though the tax cut bill passed the Senate, it did so without a single Democratic vote. Maintaining this kind of unity is an impressive feat given the intense internal squabbling that has long marked America’s political parties, and a clear example of Schumer's talents. “For my money, that is the greatest skill for a leader in the Senate,” said Sean Kelly, a former Senate Democratic policy analyst and current scholar who closely observed Schumer’s three predecessors over the decades.

But last month, this unity visibly broke down during the jockeying that led first to the government shutdown, then the shutdown's 72 hours later. On Friday, January 19, five centrist Democrats voted for a deal that would keep the government open, though enough Republicans voted no to defeat the bill. That Monday, a group of 15 progressive Democrats (plus Bernie Sanders) voted against reopening the government after Schumer came to terms with the Republicans.

The grassroots activist community, unsurprisingly, was up in arms: The point of the shutdown was to force Republicans to vote on an immigration bill to protect DREAMers. But Schumer gave in before they achieved that aim, instead only extracting a relatively weak promise from Majority Leader Mitch McConnell to debate an immigration bill on the floor. (That debate was held last week and resulted in votes on four reform proposals—all of which died.)

Many progressives cast Schumer’s performance as a betrayal to Democratic values, a failure as a leader and a negotiator. It was a compromise at a moment when the resistance-fomenting base wasn’t in the mood for a compromise. And it raised questions about Schumer’s tactics and whether his style of leadership may become a problem as the midterms approach.

Schumer has a long-standing reputation as a consummate pragmatist and dealmaker. Ross Baker, a scholar in residence for Schumer’s predecessor and close ally former Nevada Senator Harry Reid, refers to him as “a world-class schmoozer,” adept at cultivating relationships across the factions of his own party as well as across the aisle. In the past, he’s used these skills to cobble together unlikely bipartisan coalitions on hot-button issues like gun control and immigration. A savvy media manipulator, he’s also managed to avoid suffering serious damage for his more controversial votes, like his opportunistic support for Wall Street deregulation in the lead-up to the 2009 financial crisis, or for waiting to throw his weight behind gay marriage until it became politically expedient to do so.

Those skills have long positioned Schumer for a leadership role. No one was surprised when Reid tapped him as his likely successor in 2015, or when he beat out Dick Durbin for leader in 2016. That made him the most powerful elected Democrat in Washington, DC. But it also put him in a tight spot—with Donald Trump in the White House and Republicans in charge of the Senate and House, there wasn’t much he could do to stop the GOP from pursuing its goals.

But he has worked to unite an opposition party and build a new Democratic image. Upon taking power, Schumer dramatically expanded the Senate Democratic leadership team. Where Reid had a reputation for making decisions with a small cadre of allies and fighting tooth and nail with caucus members, like centrist West Virginia senator Joe Manchin, who threatened to break rank, Schumer made it a point to bring both the party’s centrist and far-left wings to the table. Colleagues say he leads by listening, obsessively checking in with and relaying details to every member of his caucus. It’s an unwieldy style, but one that operates on a sense of equality and engagement rather than backroom deals and needling. From day one, Schumer has explicitly told his caucus that they ought to vote as they see fit, while warning them about the perilous optics of voting with the GOP in the Trump era.

“Reid was known for his pugnacious personality and less afraid of collateral damage,” said Andrea Hatcher, who studies Senate leadership styles. “Schumer appears smoother… much more willing to get along and provide ‘service leadership’ to cultivate the support of his caucus.”

He’s also maintained his pragmatic core, stressing that he’s open to bipartisan dealmaking and not interested in opposition for the sake of opposition. He’s used his media savvy to blunt criticism from a fiery activist base that views concessions as a form of sacrilege. After early protests outside his Brooklyn home threatening repercussions if he were to lead the Senate to in any way compromise with Trump, he made the rounds on progressive shows and got vocal about standing against Trump nominations, all without being so incendiary and highly visible as to become a go-to far-right bogeyman a la House Minority Leader Nancy Pelosi. It’s a balance that allowed him to broker agreements with Trump in the past, like the agreement in September that funded the government through December and provided relief to hurricane-hit communities, which he accomplished with the overwhelming support of his caucus and without stirring up too much ire from activists.

Republicans have made his job easier, however. Schumer could encourage someone like Manchin to explore bipartisanship without real fear that he’d break ranks because the GOP has devoted itself to purely partisan politics. Republicans have also focused on divisive issues, like healthcare rather than, say, infrastructure; their healthcare legislation in particular was so unpopular that it was not difficult for the entire Democratic caucus to vociferously oppose it. And, Kelly points out, Schumer is at the head of a particularly homogenous caucus. Whether due to chance or increased partisan polarization in primaries and elections, there are fewer true wildcards in the mix today than there were in recent years.

“Schumer has the luxury of being minority leader with an overwhelmingly disliked president of the opposition party,” added Hatcher. “It doesn’t take much to maintain unity in opposition.”

In that context, the vote on the shutdown was a telling moment. When confronted with an issue that brought on real divisions in his caucus—some Democrats wanted to keep the government closed to force concessions from Republicans, others disagreed—Schumer couldn’t keep it together. Sure, a few Democrats had broken ranks before on big votes,like Supreme Court Justice Neil Gorsuch’s confirmation. But those votes came in the context of higher-profile, unifying debates on healthcare. This, however, was the biggest vote of the month. And for all his media savvy, Schumer couldn’t spin the shutdown as a clear win for the Democrats; the left spent the next week slamming him for “caving,” while Trump celebrated a “big win.”

“Each day as we get closer to the elections,” predicted a pessimistic Kelly. Schumer’s “going to have a tougher and tougher time because he’s probably going to have some Senators who are going to want to bolt.” That could make the Democrats seem weak and disunited.

Schumer's problem was the shutdown really did put Democrats in a tough spot. Activists may have wanted senators to use it wrest concessions out of the Trump administration, which seemed like a viable strategy initially. But as the shutdown progressed, it seemed to jeopardize the Democrats’ reputation as the responsible adults in the room, potentially putting them at greater risk in the upcoming elections. Schumer, as I wrote in the aftermath of that deal, didn’t have much choice but to take the least bad option available, even if it resulted in a lot of anger directed at him.

While Schumer’s reputation may have taken a beating from the left, he’s still a skilled negotiator. Last week, he managed to craft a bipartisan bill to fund the government through March 23 while raising budget caps, extending the debt ceiling, expanding future funding for the Children’s Health Insurance Program, providing more natural disaster relief to Puerto Rico and other areas, and boosting a host of other Democratic priorities in exchange for a boost to defense funding.

This budget deal didn’t fulfill progressive wish lists, and 11 mostly progressive Democrats did oppose it, alongside 16 mostly fiscally conservative Republicans. But it will likely play into Schumer’s narrative of the Democrats as a reasonable party that gets things done and delivers for voters. That may not be an appealing message for left-wing activist types who want Democrats to fight, but it might attract moderates who are sick of the dysfunction in the GOP.

One of Schumer’s top priorities this year is making sure his senators stay in power through November, and 25 senators who caucus with the Democrats are up for reelection, ten in states Trump won in 2016. Because Senate races are still highly localized, points out Hatcher, Schumer knows he needs to allow them to make votes that will play with their bases.

Schumer “has been willing to take heat from the progressives for shaping his positions to accommodate his red-state” senators, said Baker.

That means he likely cannot, and should not, pursue or achieve full unity in his caucus in the coming months, especially if tough votes on issues like infrastructure come up. But Schumer’s leadership, according to most of the experts I’ve spoken to, still fosters something arguably more important: intra-party comity. Making sure every member of his caucus feels heard and involved means that even when there is a break in unity, ideally it does not come with covert sniping or anything else that would signal dysfunction. Knowing when to push for unity and when to allow Senators to strip away is a serious challenge for any leader, and one that they will all likely periodically fail at. But, said Hatcher, Schumer’s balanced those imperatives well thus far.

Still, cautioned Kelly, “Senate leadership is very strange. It’s like playing with that old toy, Slime. It slips through your fingers so easily just when you think you’ve figured it out.”